Sam Pazzano, QMI Agency

TORONTO -- The former boyfriend of Qian "Necole" Liu listened helplessly by his computer's webcam in Beijing as she was attacked in her north-end home, a jury heard Monday.

In her opening, Crown attorney Christine Pirraglia said Xian Chao Meng and Liu, 23, were engaged in an online chat visually through a webcam using the Tom Skype program and a MSN-style messenger service in the late hours of April 14, 2011, and into the early hours of April 15.

While Meng never saw the deadly struggle -- which was off camera -- he heard his ex-girlfriend say "no" in both English and Mandarin to her attacker's sexual advances, Pirraglia said.

"Meng then heard two muffled bangs. He never heard a sound from Liu again," the Crown told court.

Pirraglia is alleging that Brian Dickson, 32, is the intruder who sexually assaulted the Chinese York University student.